Departments have multiple effects, but their general purpose is to divide up the helpdesk and control access.
Every ticket must have a department (but can’t have more than one).
Agents may only have permission to view tickets in certain departments.
For example, suppose your helpdesk has a Research department and a Customer Service department. You might not be able to see Research tickets; another agent might not be able to see Customer Service tickets, and a third agent might be able to see tickets in both.
The advantage of this is that you only have to sort through the tickets that are relevant to your particular role.
Assignment and following always overrule department permission.
If you’re not normally allowed to see Research department tickets, but one is assigned to you or your team by someone who can, you can then see it. Similarly, if a ticket you are following is moved to the Research department, you will still be able to see it.
You may be allowed to assign a ticket to a department that you don’t have permission to view. It depends on your permissions, which are set by your admins.
In the example above, if you found a useful customer suggestion among the Customer Service tickets, your account might let you assign it to the Research department. If you tried to access the ticket afterwards, you would see a No Permission error message.
Different departments can have different layouts for the form you use to create a ticket.
You may find that when you create tickets in different departments, different fields are present. The form layout you see as an agent is also different from what users will see.
Departments can optionally have a different name that’s visible to users. For example, your admins can create an “Abuse” department, but configure it so that users see it as “Customer Service”.